In many electronic systems, galvanic isolation is used to isolate different portions of the system from each other. For example, isolation may be used in equipment that is coupled to a data communication line, such as those found in wired local area networks in order to prevent common mode currents due to potential differences between remotely located transceivers. Galvanic isolation may also be used in medical devices that are used to treat or monitor patients in order to safely separate low current circuits from a high-voltage power supply to prevent electric shock. Further, switched-mode power supplies often use galvanic isolation to separate control circuitry from a high-power output. Moreover, connections from one electronic system or sub-system to another electronic system or sub-system often use galvanic isolation to separate the system due to safety reasons.
Generally, discrete transformers and optocouplers are used to transmit signals from one electrical circuit to another electrical circuit without direct electrical contact between the two electrical circuits. However, discrete transformers and optocouplers may be relatively large, heavy, and expensive. In the case of optocouplers, there may be problems related to the aging of optical components.
Another way to transmit signals from one electrical circuit to another electrical circuit without direct electrical contact is to use a coreless transformer. While a discrete transformer comprises a core to direct the magnetic flux, the coils of a coreless transformer may be placed in close proximity to each other to achieve adequate magnetic coupling. In many cases, the coils of the transformer may be separated by a thin dielectric. However, when coils are placed in close proximity to each other, there may be a risk of the dielectric material breaking down in the presence of high voltages, such as those encountered during electrostatic discharge events. There may also be a safety risk associated with having the coils placed in close proximity to each other.